Carpal tunnel syndrome (“CTS”), a form of repetitive stress injury, typically affects office workers who work with computers. CTS occurs when the median nerve, which relays sensation from the palm of the hand and fingers, becomes pinched, usually by swelling of the tendons. This leads to numbness and sometimes pain of the fingers, hand, and sometimes the forearm. CTS is often caused by excessive repetitive movements of the arms, wrists or hands.
Treatment for CTS first involves adjusting the way the person performs a repetitive motion. In addition, it may involve immobilizing the wrist in a splint and/or short courses of anti-inflammatory drugs or injections of cortisone or steroids in the wrist. If CTS does not respond to conservative treatment, then surgery is often the next treatment option.
Because musculoskeletal disorders, including repetitive stress injuries, account for one third of all occupational injuries reported to the Bureau of Labor Statistics annually, employers are under increasing pressure from unions, workplace safety regulators, and health care providers to address this issue. Workers can reduce the likelihood of CTS arising through simple steps such as: keeping their wrists straight when using tools; avoiding flexing and extending their wrists repeatedly; minimizing repetitive motion; and resting their wrists. Employers can help workers take these steps by replacing old tools with ergonomically designed new ones. Consequently, there is and has been a wide variety of attempts to provide ergonomically designed tools, including computer input devices such as computer mouses, to meet the resulting demand.
Ergonomic improvements in computer mouses have included: changes in mouse housing shape (for example see U.S. Pat. Nos. 6,005,553 and 6,377,244); mouse housings/rests moldable to match a user's hand (for example see U.S. Patent App. Nos. 20010024192 and 20020075236); and mouse attachments and extensions (for example see U.S. Pat. Nos. 6,396,478 and 6,417,842). Although the prior art in this area includes a wide variety of innovations, these innovations consistently rely on pressure-actuated buttons to generate output signals to the host computer.
The present invention also has the potential of increasing user efficiency and the rate of activation of signals from an input module to a host computer. It is a more natural motion to raise a finger to point at the screen (as opposed to pressing a pressure-actuated button) when selecting an object on the screen. The use of infrared switches in the present invention will enable object selection using this more natural motion. Moreover, the use of infrared switches in the present invention will enable the activation of programs in a Windows™ environment by raising a finger completely through an infrared beam and returning it back through the infrared beam to its rest position. This will generate a signal similar to the ‘double-click’ (typically used for program activation) that is often difficult for older computer users.
It is an object of the present invention to provide an input module designed to reduce stresses on users' hands by using light-based switches (infrared or laser), rather than pressure-actuated buttons, to generate output signals.
It is another object of the present invention to increase user efficiency and the rate of activation of signals from an input module to a host computer.
It is another object of the present invention to provide a means of increasing user efficiency and the rate of activation of signals from an input module to a host computer while keeping both hands free to type on a keyboard.